Glutathione (GSH) vs Pinealon (EDR)

Glutathione (GSH)

Glutathione is a tripeptide of glutamate, cysteine and glycine in which glutamate is linked through its side-chain (gamma) carboxyl group. It is made inside cells by two ATP-dependent enzymes, glutamate–cysteine ligase and glutathione synthetase, and is one of the most abundant small thiols in animal cells. It occurs in a reduced form (GSH) and an oxidised disulfide form (GSSG), and the ratio between them is widely used as a measure of cellular redox state. Its biochemistry inside the cell is well mapped. Studies that supply glutathione from outside, in animals or people, are harder to interpret because extracellular glutathione is readily broken down, and human findings in that area are inconsistent.

Pinealon (EDR)

Pinealon is the synthetic tripeptide Glu-Asp-Arg (EDR), one of the short 'bioregulator' peptides described by a Russian research group. That group proposes that very short peptides can act on gene expression directly, without a conventional receptor, a view that has had little independent testing. Most published work on Pinealon comes from the same group and its collaborators. It consists of experiments in cultured neurons and other cells, rodent studies centred on the nervous system and oxidative stress, and computer modelling of how the peptide might bind DNA. Human data are very limited.

How Glutathione (GSH) acts

The reactive part of glutathione is the thiol of its cysteine residue. Glutathione peroxidases use it to reduce hydrogen peroxide and lipid hydroperoxides, in the process oxidising two molecules of GSH to GSSG; glutathione reductase then regenerates GSH using NADPH. Glutathione S-transferases attach it to electrophilic compounds, the first step in a conjugation pathway that handles many drugs and foreign chemicals. It also forms mixed disulfides with cysteine residues in proteins, a modification studied as a form of redox signalling. Because the gamma-glutamyl bond resists most peptidases, breakdown begins with gamma-glutamyl transpeptidase on the outer surface of cells.

How Pinealon (EDR) acts

The originating group has proposed that EDR enters cells and their nuclei and binds particular DNA sequences or histone proteins, changing the expression of nearby genes. Support for this comes mainly from molecular modelling and in vitro binding experiments. In cultured neurons and other cells exposed to oxidative stress, Pinealon has been reported to lower the accumulation of reactive oxygen species and to alter ERK1/2 (MAPK) signalling, and rodent studies from the same group have measured markers of oxidative damage in brain tissue. No specific receptor for the peptide has been identified, and independent confirmation of these mechanisms is limited.

The records side by side

• Type: Glutathione (GSH), Tripeptide; Pinealon (EDR), Tripeptide
• Length: Glutathione (GSH), 3 amino acids; Pinealon (EDR), 3 amino acids
• Molecular weight: Glutathione (GSH), 307.33 g/mol; Pinealon (EDR), 418.40 g/mol
• Molecular formula: Glutathione (GSH), C10H17N3O6S; Pinealon (EDR), C15H26N6O8

Reading a comparison

A comparison places two records side by side; it does not merge them. Each description above is drawn from that compound's own record, and the two were not necessarily characterised by the same methods, at the same time, or to the same level of detail. Before comparing any attribute, it is worth establishing that both records describe the substance you think they describe — names are not identifiers, and two entries sharing a name can differ in salt form, stereochemistry or the convention used to state a mass. Where a figure carries no method beside it, the comparison is between two reported numbers rather than between two measurements.